/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2010 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

/*
     File added by Alan Buckley (alan_baa@hotmail.com) for RISC OS compatability
	 27 March 2003

     Implements mouse cursor shape definitions and positioning
*/

#include "SDL_mouse.h"
#include "../../events/SDL_events_c.h"

#include "SDL_riscosmouse_c.h"

#include "kernel.h"
#include "swis.h"

static WMcursor *current_cursor = NULL;
static WMcursor *defined_cursor = NULL;

extern int mouseInWindow;

/* Area to save cursor palette colours changed by SDL.
   Actual values will be read before we change to the SDL cursor */
static Uint8 wimp_cursor_palette[2][5] = {
    {1, 25, 255, 255, 255},
    {3, 25, 255, 255, 255}
};

static int cursor_palette_saved = 0;

void WIMP_SaveCursorPalette();
void WIMP_RestoreWimpCursor();
void WIMP_SetSDLCursorPalette();


void
RISCOS_FreeWMCursor(_THIS, WMcursor * cursor)
{
    SDL_free(cursor->data);
    SDL_free(cursor);
}

WMcursor *
RISCOS_CreateWMCursor(_THIS,
                      Uint8 * data, Uint8 * mask, int w, int h, int hot_x,
                      int hot_y)
{
    WMcursor *cursor;
    Uint8 *cursor_data;
    Uint8 *ptr;
    int i, j, k;
    int data_byte, mask_byte;

    /* Check to make sure the cursor size is okay */
    if ((w > 32) || (h > 32)) {
        SDL_SetError("Only with width and height <= 32 pixels are allowed");
        return (NULL);
    }

    /* Allocate the cursor */
    cursor = (WMcursor *) SDL_malloc(sizeof(*cursor));
    if (cursor == NULL) {
        SDL_SetError("Out of memory");
        return (NULL);
    }

    /* Note: SDL says width must be a multiple of 8 */
    cursor_data = SDL_malloc(w / 4 * h);
    if (cursor_data == NULL) {
        SDL_free(cursor);
        SDL_SetError("Out of memory");
        return (NULL);
    }

    cursor->w = w;
    cursor->h = h;
    cursor->hot_x = hot_x;
    cursor->hot_y = hot_y;
    cursor->data = cursor_data;


/* Data / Mask Resulting pixel on screen 
   0 / 1 White 
   1 / 1 Black 
   0 / 0 Transparent 
   1 / 0 Inverted color if possible, black if not. 
*/
    ptr = cursor_data;

    for (i = 0; i < h; ++i) {
        for (j = 0; j < w / 8; ++j) {
            data_byte = *data;
            mask_byte = *mask;
            *ptr++ = 0;         /* Sets whole byte transparent */
            *ptr = 0;
            for (k = 0; k < 8; k++) {
                (*ptr) <<= 2;
                if (data_byte & 1)
                    *ptr |= 3;  /* Black or inverted */
                else if (mask_byte & 1)
                    *ptr |= 1;  /* White */
                if ((k & 3) == 3)
                    ptr--;
                data_byte >>= 1;
                mask_byte >>= 1;
            }

            ptr += 3;
            data++;
            mask++;
        }
    }

    return (cursor);
}

int
RISCOS_ShowWMCursor(_THIS, WMcursor * cursor)
{
    current_cursor = cursor;

    if (cursor == NULL) {
        _kernel_osbyte(106, 0, 0);
        defined_cursor = NULL;
    } else {
        WMcursor *old_cursor = defined_cursor;

        if (cursor != defined_cursor) {
            Uint8 cursor_def[10];

            cursor_def[0] = 0;
            cursor_def[1] = 2;  /* Use shape number 2 */
            cursor_def[2] = cursor->w / 4;      /* Width in bytes */
            cursor_def[3] = cursor->h;  /* Height (h) in pixels */
            cursor_def[4] = cursor->hot_x;      /* ActiveX in pixels from left */
            cursor_def[5] = cursor->hot_y;      /* ActiveY in pixels from top */
            cursor_def[6] = ((int) (cursor->data) & 0xFF);      /* Least significant byte of pointer to data */
            cursor_def[7] = ((int) (cursor->data) >> 8) & 0xFF; /* ... */
            cursor_def[8] = ((int) (cursor->data) >> 16) & 0xFF;        /* ... */
            cursor_def[9] = ((int) (cursor->data) >> 24) & 0xFF;        /* Most significant byte of pointer to data */

            if (_kernel_osword(21, (int *) cursor_def) != 0) {
                SDL_SetError("RISCOS couldn't create the cursor to show");
                return (0);
            }
            defined_cursor = cursor;
        }

        if (old_cursor == NULL) {
            /* First time or reshow in window, so save/setup palette */
            if (!cursor_palette_saved) {
                WIMP_SaveCursorPalette();
            }
            WIMP_SetSDLCursorPalette();
        }

        _kernel_osbyte(106, 2, 0);
    }

    return (1);
}

void
FULLSCREEN_WarpWMCursor(_THIS, Uint16 x, Uint16 y)
{
    Uint8 move_block[5];
    int eig_block[3];
    _kernel_swi_regs regs;
    int os_x, os_y;

    eig_block[0] = 4;           /* X eig factor */
    eig_block[1] = 5;           /* Y eig factor */
    eig_block[2] = -1;          /* End of list of variables to request */

    regs.r[0] = (int) eig_block;
    regs.r[1] = (int) eig_block;
    _kernel_swi(OS_ReadVduVariables, &regs, &regs);

    os_x = x << eig_block[0];
    os_y = y << eig_block[1];

    move_block[0] = 3;          /* Move cursor */
    move_block[1] = os_x & 0xFF;
    move_block[2] = (os_x >> 8) & 0xFF;
    move_block[3] = os_y & 0xFF;
    move_block[4] = (os_y >> 8) & 0xFF;

    _kernel_osword(21, (int *) move_block);
    SDL_PrivateMouseMotion(0, 0, x, y);
}


/* Reshow cursor when mouse re-enters the window */
void
WIMP_ReshowCursor(_THIS)
{
    defined_cursor = NULL;
    cursor_palette_saved = 0;
    RISCOS_ShowWMCursor(this, current_cursor);
}

void
WIMP_WarpWMCursor(_THIS, Uint16 x, Uint16 y)
{
    _kernel_swi_regs regs;
    int window_state[9];
    char block[5];
    int osX, osY;

    window_state[0] = this->hidden->window_handle;
    regs.r[1] = (unsigned int) window_state;
    _kernel_swi(Wimp_GetWindowState, &regs, &regs);

    osX = (x << this->hidden->xeig) + window_state[1];
    osY = window_state[4] - (y << this->hidden->yeig);

    block[0] = 3;
    block[1] = osX & 0xFF;
    block[2] = (osX >> 8) & 0xFF;
    block[3] = osY & 0xFF;
    block[4] = (osY >> 8) & 0xFF;

    regs.r[0] = 21;
    regs.r[1] = (int) block;
    _kernel_swi(OS_Word, &regs, &regs);
    SDL_PrivateMouseMotion(0, 0, x, y);
}

int
WIMP_ShowWMCursor(_THIS, WMcursor * cursor)
{
    if (mouseInWindow)
        return RISCOS_ShowWMCursor(this, cursor);
    else
        current_cursor = cursor;

    return 1;
}

SDL_GrabMode
RISCOS_GrabInput(_THIS, SDL_GrabMode mode)
{
    /* In fullscreen mode we don't need to do anything */
    if (mode < SDL_GRAB_FULLSCREEN) {
        _kernel_swi_regs regs;
        unsigned char block[9];
        block[0] = 1;           /* Define mouse cursor bounding block */

        if (mode == SDL_GRAB_OFF) {
            /* Clip to whole screen */

            int r = (this->hidden->screen_width << this->hidden->xeig) - 1;
            int t = (this->hidden->screen_height << this->hidden->yeig) - 1;

            block[1] = 0;
            block[2] = 0;       /* Left */
            block[3] = 0;
            block[4] = 0;       /* Bottom */
            block[5] = r & 0xFF;
            block[6] = (r >> 8) & 0xFF; /* Right */
            block[7] = t & 0xFF;
            block[8] = (t >> 8) & 0xFF; /* Top */
        } else {
            /* Clip to window */
            unsigned char window_state[36];

            *((int *) window_state) = this->hidden->window_handle;
            regs.r[1] = (unsigned int) window_state;
            _kernel_swi(Wimp_GetWindowState, &regs, &regs);

            block[1] = window_state[4];
            block[2] = window_state[5];
            block[3] = window_state[8];
            block[4] = window_state[9];
            block[5] = window_state[12];
            block[6] = window_state[13];
            block[7] = window_state[16];
            block[8] = window_state[17];

        }

        regs.r[0] = 21;         /* OS word code */
        regs.r[1] = (int) block;
        _kernel_swi(OS_Word, &regs, &regs);
    }

    return mode;
}

/* Save mouse cursor palette to be restore when we are no longer
   defining a cursor */

void
WIMP_SaveCursorPalette()
{
    _kernel_swi_regs regs;
    int colour;

    for (colour = 0; colour < 2; colour++) {
        regs.r[0] = (int) wimp_cursor_palette[colour][0];
        regs.r[1] = 25;
        /* Read settings with OS_ReadPalette */
        if (_kernel_swi(0x2f, &regs, &regs) == NULL) {
            wimp_cursor_palette[colour][2] =
                (unsigned char) ((regs.r[2] >> 8) & 0xFF);
            wimp_cursor_palette[colour][3] =
                (unsigned char) ((regs.r[2] >> 16) & 0xFF);
            wimp_cursor_palette[colour][4] =
                (unsigned char) ((regs.r[2] >> 24) & 0xFF);
        }
    }

    cursor_palette_saved = 1;
}

/* Restore the WIMP's cursor when we leave the SDL window */
void
WIMP_RestoreWimpCursor()
{
    int colour;

    /* Reset to pointer shape 1 */
    _kernel_osbyte(106, 1, 0);

    /* Reset pointer colours */
    if (cursor_palette_saved) {
        for (colour = 0; colour < 2; colour++) {
            _kernel_osword(12, (int *) wimp_cursor_palette[colour]);
        }
    }
    cursor_palette_saved = 0;
}

/* Set palette used for SDL mouse cursors */
void
WIMP_SetSDLCursorPalette()
{
    /* First time set up the mouse colours */
    Uint8 block[5];

    /* Set up colour 1 as white */
    block[0] = 1;               /* Colour to change 1 - 3 */
    block[1] = 25;              /* Set pointer colour */
    block[2] = 255;             /* red component */
    block[3] = 255;             /* green component */
    block[4] = 255;             /* blue component */
    _kernel_osword(12, (int *) block);

    /* Set colour 3 to back */
    block[0] = 3;               /* Colour to change 1 - 3 */
    block[1] = 25;              /* Set pointer colour */
    block[2] = 0;               /* red component */
    block[3] = 0;               /* green component */
    block[4] = 0;               /* blue component */
    _kernel_osword(12, (int *) block);
}

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